12=3y-y-4y

Solution for 12=3y-y-4y equation:

Simplifying
12 = 3y + -1y + -4y

Combine like terms: 3y + -1y = 2y
12 = 2y + -4y

Combine like terms: 2y + -4y = -2y
12 = -2y

Solving
12 = -2y

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '2y' to each side of the equation.
12 + 2y = -2y + 2y

Combine like terms: -2y + 2y = 0
12 + 2y = 0

Add '-12' to each side of the equation.
12 + -12 + 2y = 0 + -12

Combine like terms: 12 + -12 = 0
0 + 2y = 0 + -12
2y = 0 + -12

Combine like terms: 0 + -12 = -12
2y = -12

Divide each side by '2'.
y = -6

Simplifying
y = -6